Abstract:

The international environment is becoming increasingly complex， with major uncertainties occurring frequently. Against this backdrop， economic policy uncertainties in various countries around the world have soared and spilled over across borders through various channels. A global spillover network of economic policy uncertainties has gradually formed， putting the economic stability of countries around the world under great threat. In this context， it is necessary to conduct an in-depth exploration of the global economic policy uncertainty spillover network structure. So， what are the structural characteristics of the global economic policy uncertainty network as a whole？ What are the evolving trends？ Complex association network often exhibit hierarchical structures， which， from a global perspective， are composed of micro-associative structures formed by multiple individual members. Therefore， what micro-structural characteristics exist in the network of economic policy uncertainty spillovers among countries globally？ What are the patterns of spillover， spillover agglomeration and the time-varying nature of both across countries globally？ Furthermore， what factors affect the spillover network structure of economic policy uncertainty？ What relationships exist between dynamic spillover network structures？ Addressing these questions may significantly reduce the difficulty of controlling global spillovers of economic policy uncertainty.The time-varying spillover indexes of economic policy uncertainty in 19 major countries （regions） from 2003 to 2020 are constructed. On this basis， from the perspective of network multi-layer structure， the social network analysis method is used to analyze the overall characteristics of the global spillover network of economic policy uncertainty， and the micro-structural characteristics of the spillover network， such as the basic spillover unit （motif） characteristics and sub-network structure characteristics. And then， the QAP analysis is used to explore the evolution inertia of the spillover network and the influencing factors of the spillover network structure. The results imply that， first， the global spillover effect of economic policy uncertainty is closely related to the impact of major events， and the spillover network and its structure own obvious time-varying characteristics. Second， the tightness of the transnational spillover network of economic policy uncertainty and the breadth and depth of the spillover of economic policy uncertainty are on the rise. There is a gradual convergence of the network centrality across countries （regions）， and the regional spillover pattern in the network is gradually changing to the central spillover pattern. The multi-center characteristics of the spillover network are increasingly obvious. Third， the situation of passively absorbing the spillover effects of economic policy uncertainty of other countries in China has improved， and the spillover correlation of economic policy uncertainty of China presents regional characteristics； Hong Kong mainly plays the role of economic policy uncertainty spillover transfer station. Fourth， there is a certain continuity and stability in the spillover relationship of economic policy uncertainty among countries （regions）； the foreign trade linkages of economies， the influence of the economies and the previous network spillover structure are important foundations for the formation and transformation of the spillover relationship of economic policy uncertainty among countries （regions） at this stage.It can broaden the research perspective of the cross-country spillover effect of economic policy uncertainty， enrich the literature on the spillover effect of economic policy uncertainty and its influencing factors， and provide theoretical support and decision-making reference for governments to effectively prevent and control uncertainty risk spillover shocks in this paper. Some important policy recommendations of this paper are as follows： first， government departments should pay close attention to the degree and dynamics of the economic policy uncertainty correlation between other countries and China， and establish a long-term mechanism for external economic policy uncertainty risk prevention policies； second， China should strengthen regulatory cooperation with other countries and strive to achieve comprehensive and multi-faceted information communication； third， while strengthening regional economic development， China still needs to pay attention to the regional prevention and control of economic policy uncertainty risks and Hong Kong’s status as a “transfer station” for economic policy uncertainty， enhancing Hong Kong’s risk identification and resilience.

Key words: economic policy uncertainty, spillover network, basic spillover units, spillover sub-network